Mastic tile



Patented Nov. 1, 1938 z,135,us

UNITED STATES PATENT OFFICE 2.13am

n Drawing. Application March 15, 1931, Serlal No. 130,9. Renewed Augnat lhl! 9Claims. (CLzoc-m' This invention; relates to a composition of matter which has its primary utility as a binder in mastic tile, and which has other additional utilities.

Fundamentally, my invention consists in utilizing a specific synthetic pitch to replace pitches of animal, vegetable, and marine origin previously used in the binding material of mastic tile; and in the use with the synthetic pitch of other materials made desirably usable in combination with the synthetic pitch by the characteristics of the latter. The synthetic pitch which I use is a variant product under the procedure disclosed in my co-pending application Serial No. 62,045, filed February 3, 1936.

In the manufacture of mastic tile certain types of binder have become substantially standard for mastic tile of different grades. Thus when the darker and less valuable grades of mastic tile are made, it is customary to utilize as a binder composition a mixture of gilsonite and steam-blown asphalt, or a mixture of gilsonite and a pitch of animal, vegetable, or marine origin; for a mastic tile of medium color, it is customary to use an animal, vegetable, or marine pitch and a coumarone resin of medium color, such as a coumarone resin of what is known in the resin industry as a No. 5 color intensity; for light-colored mastic tile, it is customary to use for the binder material a composition of lightcolored coumarone resin, such as a coumarone resin of a No. 1 or No. 2 color intensity, or lighter, and the lightest possible grade of animal, vegetable, or marine pitch, of which lightest colored pitch whale-pitch is an example.

Coumarone resin is a preferred resin component of a tile binder composition, because of its resistance to alkalies. When, however, a manufacturer is satisfied to sacrifice alkali re- 0 sistance in the tile, the coumarone may be replaced by ester gum, modified phenolic resins, and other resins having in degree an acidic character. Pitches are inherently dark in color, which may largely be attributed to the fact that the pitches of animal, vegetable, or marine origin are residual products of refining to obtain purified animal, vegetable, or marine oils and the resin content serves to decrease the penetration and elasticity of the composition, while raising the compositions melting-point. While coumarone resin and the other resins which may be used in the binder composition are satisfactorily standardized, the pitches being primarily residual products are not as initially available oi uniform quality in spite of uniformity in the nature of the material and the nature of the process by which they are derived. Even if one refiner, engaged in the refining of cottonseed oil, be taken as a source of cottonseed pitch for example, the pitch of that refiners product will vary from time to time. Since the residual pitches represent a relatively small volume of the oil, grease, or the like, subjected to refining, as usually sold they are from a variety of sources, and are produced from a variety of different raw materials and by varied processes. Adjustment to varying qualities of different pitches which may be. avaflable from time to time is therefore a diflicult incident to the manufacture of mastic tile. 7

In connection with the above, it will be noted that there are certain qualities of a binder composition for mastic tile which must come within relatively rigid specifications, thus increasing the difliculty of producing a satisfactory binder composition. Thus it has been generally considered that a mastic tile binder or binder composition should have a melting-point between 150 F. and 200 F. and preferably in the neighborhood of 170 F. It is also taken as standard practice that a mastic tile binder or binder composition should have by the New York Testing Laboratory penetrometer a penetration of 2-6 at 77 F'. under a gram load for 5 seconds, and a. penetration of 20-25 by the New York Testing Laboratory penetrometer at F. under a 100 gram load for 5 seconds.

It is important that a binder material or composition for mastic tile should not possess in too high a degree the quality of-thermoplasticity, but, conversely, that its penetration at normal atmospheric temperatures, and within a reasonable range thereabove, should not be too great.

It is necessary that a binder composition, or material, for mastic tile possess in degree thermoplasticity in order that pigments or fillers may be worked into it, as by mastication on hot rolls or in mixers, this thermoplasticity being typical of resins and partially typical of pitches. Pitches, however, comprise in their physical make-up a gel structure which gives the qualities of elas-' ticity and penetration at lower temperatures, and

which is opposed to the quality oi thermoplasticity. As noted, the character of pitches is so variable that the available pitches of animal, vegetable, and marine origin cannot be considered as having a fixed value in any of their qualities for apportionment with resins and other tile ingredients.

By making a binder composition formastictile in which the content having'gel structn'reis of synthetic origin; "and of standardized quality, a

binder composition may be made up in accordance with fixed proportions of the pltchy content and of the resin content in correspondence with the qualities desired in the tile. Also by making a binder composition in which a synthetic pitch of particular sort is incorporated, the pitch content of the binder composition may be of itself so light in color that it is not necessary to depend upon,

the resin content of the binder composition in order that thetile may be pigmented-in light shades or tones. v in the binder composition is much lighter in color intensity than the lightest grade of vegetable, animal, or marine pitch commercially available.

. Its .use, therefore, l v s a lighter composition for resin of any particular color depth with which-it is used, and permitsa light shade of tile to be made without utilizing an excessive quantity of pigment.

Thus taking any color depth'for a binder composition compounded of the synthetic pitch which "of the binder composition for tile is substantially the product disclosedin my co-pending. application. Serial No. 62,045, to which reference has been above made. This synthetic pitch is obtained by oxidizing together to a sufliciently high point of oxidation a drying oil and still residue derived from the distillation, fractionation, or purification of the light oil recovered from by-product coking of coal, or equivalently from the redistillation of a coal-derived drip oil. Referring to the by-product coking of the coal, the light oil comes over in the coal distillation, and is recovered from the gases with which it comes over by absorption in a scrubbing oil,'which. is commonly a heavy cut of petroleum. The still residue resulting from the fractionation and purifying treatment of this light oil contains polymers of resin-forming bodies in various stages of polymerization, some of these polymers being relatively heavy, and other substances which maybe regarded as impurities. It is a dark viscous oily substance, deficient in drying qualities, and as it is commercially available may be obtained from one or more of several operations conducted upon the lightoil.

One such sourceof still residue 'is the still in which the light oil is purified and fractionated to give crude benzol, crude toluol, No. 1 crude solvent naphtha (crude xylol), and No. 2 crude solvent naphtha. The residuum from this fractionation consists largely of heat polymers, and is knownin the trade as "crude. still" residue, The fractions from the crude still, after washing with sulphuric The synthetic pitch which I use aromas acid and neutralized, are distilled in what are known in the trade as "pure stills". The residues from the distillation of these fractions comprise primarily acid polymers and heat polymers, and comprise also sulphonates. The residues from a the pure still contain also sulphates from acid purification and neutralization which have not been wholly removed by washing. This pure still 1 residue normally is mixed in a tank with the "crude residue, that,:as it is commercially available, still residue contains at least the residual products'from these two types of still dealing with coke-oven light oil and its fractions. Usually there is also mixed in with these two still residue'sinthe residue tank a third residue, which ,comprises bottoms from the distillation of the heavier cuts ofgNo. 1 and No. 2 crude solvent naphtha.

terial itmay be oxidized to produce an elastic and pliable material.

The synthetic pitch which I utilize as a com ponent of a binder composition for mastic tile is produced by conducting oxidizing treatment simultaneously upona mixture of the above-described still residue and one or more drying oils. By oxidizing these substances simultaneously in admixture, the'still residue and the drying oil remain compatible, and the mixed product (the synthetic pitch) is homogeneous under all normal conditions, the components of the mixture being solublein each other in all proportions. In producing specifically synthetic pitch for tile use, oxidation of the still residue and dryingoil mixture is carried to an extreme point to produce a homogeneous solid, soluble in selected solvents. The degree to which a mixture of the still residue and drying oil is oxidized for this purpose is higher than thatto which drying oil alone may conveniently be oxidized in commercial practice. For example, the drying oils may commercially be oxidized to a ,point'at which they acquire a viscosity of approximately 1500 Sayboltat 210 F. When it is attempted to oxidize a dryingoil or a mixture of drying oils to a viscosity higher than about 1500 Saybolt at 210 F., gelling of the oil renders it extremely difilcult to handle on a commercial scale,-and' a gel structure in the oil being developed to such a high degree, the oil becomes lacking in thermoplastic properties. Also attempted progressive oxidation of drying oil above a viscosity of 1500 Saybolt at 210. F. places the oil in such condition that its lack of thermoplasticity practically inhibits. the passage of an oxidizing gas through it. a

By oxidizing a mixture of the still residue and drying oil it is possible in commercial practice to reach a; much further advanced stage of oxidation, and to attain in the mixed product a 'viscosity of 4000 Saybolt at 210 F., and much higher. This is for the reason that the still residue, by its inherent thermoplasticity, retained in part even after a relatively high degree of 'oxidation, helps passage of -air and disperses. the gel structure of the oil as it oxidizes. As carried to such high viscosity, the oxidized mixture st'ill retains suflicient thermoplasticity to permit its ture.

a,1ac,4aa 1 3 ready removal from a treating vessel in which it is blown.

Even at such high stage of the oxidation the components of the pitch remain so compatible that the product is homogeneous. In the brief description of its production which will follow, it should be understood that any form of the apparatus found suitable for the purpose may be used, and that oxygen or any otherwise suitable oxygen-containing gas may be used to cause oxidation. It is most economical and convenient to utilize atreating vessel provided with heating coils and with perforated coils leading to a blower of adequate force and capacity, to supply to the material undergoing treatment air in relatively great volume and at adequate pressure.

As an exemplary description of a commercially suitable mode in which the oxidizing process may be conducted, a mixture of drying oil, such as linseed oil, fish oil, or the like, and the liquid still residue is introduced into a vessel of the sort indicated, and while it is gently heated air is passed upwardly through the body of the mix- While for various purposes the period of oxidation and the relative proportion of the drying oil and the still residue may be varied within wide limits, as discussed in my co-pending application to which reference has been made, the limits appropriate to the production of a synthetic pitch purposed for incorporation in the binder composition of mastic tile, and for analogous purposes, are in certain respects more restricted. To explain, since the mixture is to be carried to so high' a ,viscosity, the still residue should in any event substantially equal the drying oil in the mixture, and the time of treatment, regard being had to the proportions of the mixture, must be adequate to bring the mixture to the desired high stage of oxidation.

I shall give specific examples of the production of various exemplary pitches used as a component in a binder composition for mastic tile, as follows:

Example N0. 1

12000 pounds of a mixture consisting of by weight of the still residue and 40% by weight of drying oil was oxidized, the initial temperature under which oxidation was conducted being approximately 170 F. The initial viscosity of the mixture was 140 Saybolt at 210 F. After oxidation by air blowing for a period of 4% days the viscosity had been raised to about 1800 Saybolt at 210 F. The temperature was then raised to about 200 F. and from this point viscosity increase was rapid. After a total oxidation treatment for 6 days the viscosity exceeded 5000 Saybolt at 210 F., the treating temperature in the Taking a mixture comprising 70% by weight of the still residue and 30% by weight of drying oil, air was blown through this mixture at an initial treating temperature of 200 F., and at the end of a 6 day treatment, the temperature being from time to time raised up to a maximum of 245 F. to keep the material sufliciently thin for the passage of air, a solid having a meltingpoint substantially above F. was produced. The initial viscosity of this still residue and drying oil mixture was from to Saybolt at 210 F.

It will be understood that the proportion of still residue and drying oil may be varied, since I have utilized a mixture containing as highas 80% by weight of still residue, andhave found suitable for my purpose mixtures lying between 40% by weight of still residue and 80% by weight of still residue. The question of the synthetic sible to use a synthetic pitch which does not have 1 a viscosity greatly exceeding 1500 Saybolt at 210 E, which is approximately the maximum viscosity to which drying oil is commonly carried by oxidation in commercial practice. It is, of

course, desirable, as will be hereinafter explained,-

to utilize a pitch oxidized to high viscosity'in order that the melting-point of the resin, with which the synthetic pitch is compounded to make the binder composition, need not be high.

As explained initially herein, a binder composition for use in mastic tile must conform to certain relatively fixed requirements as to penetra- .tion at 77 F. and penetration at 115 F., and an adequate degree of thermoplasticity is also a practical requirement. As indicated, an outstanding advantage of the use of this synthetic pitch in a binder composition is that it gives pitch in any required quantity which is uniform in its characteristics of penetration and thermoplasticity, these qualities of the synthetic pitch being determined during its manufacture. Thus, by combining the pitch with a resin of standardized qualities a binder composition having the necessary characteristics may be made up without added experimentation into the qualities of the pitch.

In the binder composition the synthetic pitch contains a highlydeveloped gel structure and is thus capable of imparting to the composition the desired quality of elasticity and penetration at normal atmospheric temperatures. For this same reason, also, the penetration of the pitch does not increase rapidly with rise of temperature,the synthetic pitch showing remarkable stability in that respect. For example, I have found the synthetic pitch as produced in Example No. 1 above to have a penetration at 115 F. not approximate- 1y exceeding 2% times its penetration at 77F. This uniformly low ratio in penetration with increase in temperature serves'in a binder composition comprising a resin to offset thehigh ratio of penetration with increase in temperature characteristic oi the resins, and as above stated' its uniformity specifically renders it more advantageous than pitches of variable penetration for blending with resins to obtain-a'com'position of the desired penetration characteristics. 1

It is understood in the manufacture of mastic tile that in a binder composition the pitch, although it itself does not have a definite melting.-

point, none the less in composition'with the resin" serves greatly to decrease the melting-point from I that of the resin. My synthetic. pitch, however,

when carried to high'viscosity in greatly decreased degree causes lowering in melting-point below the melting-point of the resin. For example, tov parallel current practice with new practice, a our- 1 rent'practice would consistof melting together two parts of resin, having a melting-pointof 230 F., ball and ring, with one part of palm pitch of whatmay roughly be considered average qualities.

The combinedmaterial has a melting-point of the mixture of 161 F., a penetration of 3 at 77 F., and .a penetration 0124 at 115 F. Iparallel this with a mixture of 1 part by weight of synthetic pitch having a viscosity of 4300 Saybolt at 210 F., and -2 parts of resin having a melting-point of 180 F., to give a composition having a melting-point of 163 F., a penetration of 3 at 77 F.,

. and a penetration of 16 at 115 1''.

It is therefore possible, by using a binder which comprisesmyisynthetic pitch and resin, to utilize a resin of lower melting-point than would be possible when using one of the .usual animal, vegetable, or marine pitches. In this connection it should be emphasized that the uniformity of the synthetic pitch permits one confidently to use it with a resin of given melting-point, the effect of mixing the pitch and the resin to form a complete binder being accurately predictable without experimentation as to the pitch, and naturally without experimentation as to the standardized resin.

A noteworthy quality of my syntheticJpitch is its low color intensity, and its clarity. Whereas the pitches commonly employed are. very dark, and-greatlyincrease the natural color .depth of a .tile which comprises a binder including them,

my synthetic pitch has a color intensity approximating what is-known on the coal tar resin color scale as a No. 10 to a No. 12 color. Thus saving may be effected by greatly decreasing the quantity partof the pitch to obtain a binder material havingapproximately a No. 12 color intensity. Tile made up with the usual filling material may be used with moderate quantities of the medium color pigments, such as Spanish oxide, F'rench ochre, raw umber, chrome greens, chrome yellows, and the like, without throwing those pigments oiI cast. It may be additionally noted that a coumarone resin or No. 13 color, which asnoted is considered a very darkresin, may be aproduct which is obtained by purification and distillation from the same still residue which in oxidized form constitutes a substantial proportion of the-pitch. A v

No. coumarone resin or a resin corresponding to aNo. 5 color on the same scale would be required to give a color No. 14 binder made up of 2 parts of the resin and 1 part of the pitches commonlyemployed.

By combining a resin of No. 5 color'intensity with mysynthetic pitch I obtain a binder material of No. 9 color; whereas a resin of No. 1 color to No. 2 color would be required to obtain a binder I of No. '10 color'when combined in the same proportion with animaL vegetable, or marine pitches.

This is considered tobea light binder composition and is used with what are commonly considered light pigments, such as light greys, creams, and

thelike.

Further to consider the question of color, by using my syhthetic pitchas a componento'f a binder composition for tile, I am able to obtain a white tile with a reasonable quantity of pigment. The binder composition for such tile comprises 1 part or mysynthetic pitch to 2 parts of resinot a color N0. 1, orlessercoloration. It may be noted that the production of white tile, and very delicate shades of pink, or the like, has notbeenpossible without using relatively large amounts of pigment and high strength pigments, such as titanium oxide, which is an expensive material.

It is usual practicein making mastic tile to commingle the binderingredients,the filling material, and the pigment on.or just before they are placed upon hot, masticating rolls. My synthetic.

pitch, as well as the resins usable with it, being standardized in its characteristics, I am-enabled to make up abinder composition, which is itself standardized, merely by fusing together the synthetic pitch and the resin. This may be utilized in manufacturing the tile as a complete binder without apportionment of pitch and resin during the process of tile making. The synthetic pitch as disclosed herein is thoroughly compatible with the coumarone resins, which resins, because of their relatively low cost and advantageous qualities of chemical inertness and. waterproofing qualities, their high melting-point, and particularly because of their chemical inertness and resistance to alkalies, are the resins commonly used.

in mastic tile. Other resins, however,*are comi 3 patiblewith the synthetic pitch and are capable of forming with it binder compositions which are in many respects satisfactory. Thus making due allowance for their several characteristics, I may combine with the pitch ester gum, modified phenolic resin, petroleum resin, modified glyptal resin, and in general any resin which may be satisfactorily used as a tile resin with pitches of animal, vegetable, or marine origin. There is still.

another advantage of a binder composition comprising my described synthetic pitch and a resin. That is, that whereas it is usual'commercial practice to incorporate in mastic tile filler in aIratio tion, thoroughly satisfactory results may be obtained by using as high a ratio as 3:1 of fillin material with my binder composition.

v I claim as my' invention:

1. A binder composition for mastic tile com prising a thermoplastic resin compatible with animal, vegetable and marine pitches, and a synthetic pitch compositeof at least one drying oil and a substantial proportional content of still residue from the treatment of light oil derived in the by-product coking of coal oxidized in admixture to a-viscosity higher than 1500 Sayboltzat 210 F. v

'2. A mastic tile comprising filling material of conventional sort, and a binder compositioncomprising a thermoplastic resin compatible with a'n-' imal, vegetable and marine pitches and a synthetic pitch composite of at least one dryingoil and a substantial proportional content of still residue from the treatment of light oil derived in the by-product coking of coal the drying oil ahd of no more than 2.25 to 1 of the binder composir still residue being oxidized in admixture to a viscosity higher than 1500 Saybolt' at 210 F., in the said mastic tile the conventional filling mate.-

rial being included in a proportion by weight or substantially more than 2.25 parts of filling material to each part of binder.

3. A binder composition for mastic tile comprising a thermoplastic resin compatible with animal, vegetable and marine pitches having a color intensity exceeding 10 on the coal tar resinscale, and a synthetic pitch composite of at least one drying oil and a substantial proportional content of still residue from the treatment of light oil derived in the by-product coking of coal oxidized in admixture to a viscosity higher than 1500 Saybolt at 210 F.; the binder composition having as such a color intensity not exceeding the color intensity of the resin included in the binder composition.

4. A binder composition for mastic tile comprising a thermoplastic resin compatible with animal, vegetable and marine pitches having a color intensity exceeding 10 on the coal tar resin scale, and a synthetic pitch composite of at least one drying oil and a substantial proportional content of still residue from the treatment of light oil derived in the by-product coking of coal oxidized in admixture to a viscosity higher than 1500 Saybolt at 210 F., the binder composition having as such a color intensity not exceeding the color intensity of the resin included in the binder composition.

5. A binder composition for mastic tile comprising dark coumarone resin produced by the distillation of a still residue from the treatment of light oil derived in the by-product coking of coal and having a color intensity exceeding 10 on the coal tar resin scale, and a synthetic pitch composite of at least one drying oil and a substantial proportional content 01' the same still residue from which the resin is producible oxidized in admixture to a viscosity higher than 1500 Saybolt 210 F., the binder composition having as such a color intensity not exceeding the color intensity of the resin included in the binder composition.

6. A binder composition suitable for inclusion in white and delicately tinted mastic tile comprising a thermoplastic resin compatible with animal, vegetable and marine pitches of low color intensity, and a synthetic pitch composite of at least one drying oil and a substantial proportional content of still residue from the treatment of light oil derived in the by-product coking of coal oxidized in admixture to a viscosity higher than 1500 Saybolt at 210 F. and having a color intensity not substantially exceeding 10 to 12 on the coal tar color scale.

'7. A binder composition for mastic tile comprising a thermoplastic resin compatible with animal, vegetable and marine pitches, and a synthetic pitch composite of at least one drying oil and a substantial proportional content of still residue from the treatment of light oil derived in the by-product coking of coal oxidized in admixture to a viscosity higher than 1500 Saybolt at 210 F. and having a color intensity not substantially exceeding 10 to 12 on the coal tar color scale.

8. A binder composition suitable for inclusion in white and delicately tinted mastic tile comprising a thermoplastic resin compatible with animal, vegetable and marine pitches of low color intensity, and a synthetic pitch composite of at least one drying oil and a. substantial proportional content of still residue from the treatment of light oil derived in the by-product coking of coal oxidized in admixture to a viscosity higher than 1500 Saybolt at 210 F., the said synthetic pitch I having a color intensity not substantially exceeding 10 to 12 on the coal tar color scale.

9. A binder composition for mastic tile comprising a thermoplastic resin compatible with animal, vegetable and marine pitches, and a-synthetic pitch composite of at least one drying oil and a substantial proportional content of still residue from the treatment of light oil derived in the by-product coking of coal oxidized in admixture to a viscosity higher than 1500 Saybolt at 210 FL, the said synthetic pitch having a color intensity not substantially exceeding 10 to 12 on the coal tar color scale.

FRANK W. CORKERY. 

